The electric fence industry is highly regulated with restrictions being placed on various electrical parameters associated with electric fences. For instance, there are restrictions on the maximum amount of energy output from an electric fence energiser, the maximum current allowed as well as maximum voltages set according to the load under which the energiser is placed.
Unfortunately, these standards do not mimic the operating characteristics of standard electric fence energisers and therefore electric fence energisers have not been able to achieve an optimum performance within those standards.
For example, one set of operating standards specifies a simple step function for output voltage according to energiser load. A standard electric fence energiser has its output voltage varying with load as well, but with a function which is represented by a shallow curve. In order for a standard energiser to meet the lower voltage requirements for the lower energiser load (in ohms) the maximum output voltage from the energiser at the higher loads is significantly less than that allowed under the standards.
This is of concern, as the present inventors have found that an electric pulse propagates along an electric fence line more readily if there is provided a higher output voltage. Further, a high voltage pulse is preferable for physiological reasons as a high voltage pulse can deliver a shock of greater magnitude through the body of an animal more effectively than a low voltage pulse.
Another problem with electric fence energisers is that occasionally conductive material may fall on the fence and create a continual current drain on the energiser causing it to become undesirably hot.
A further problem is that over a period of time, long grass may grow against the electric fence providing a conductive path. This allows increased current to flow and causes the output voltage on the fence to drop. This is obviously undesirable as the effectiveness of the fence pulses has now been reduced.
It is an object of the present invention to address the above problems, or at least to provide the public with a useful choice.